Endometrial dating

Red blood cells and neutrophils are mixed between the involuting structures.ovulation secretory phase / luteal phase Endometrial biopsy The best way to prove or disprove that ovulation has taken place is to take an endometrial sample on cycle day 22 or later, preferably at the onset of uterine bleeding.In any case, one should not average cycle days and report ’POD 3 or 17th-day secretory endometrium’.Endometrial biopsies are not to be taken at the onset of bleeding in the following two conditions: if luteal phase defect (LPD) is suspected clinically and is desired to be confirmed histologically, when the biopsy should be taken between POD 7 (21st) and POD 9 (23rd) cycle days to demonstrate a 3–4 day delay in endometrial maturation; or if there are asynchrony of gland/stromal development and dissimilar maturation in different regions of the endometrial specimen.In the mid-secretory phase (days 5-11 post-ovulation or days 19-25 of the cycle), the glands remain dilated, but become more irregular with a papillary or saw-tooth appearence.The vacuoles move to a supranuclear position and the contents may be seen within the lumina.Thus, studies that clearly delineate which histologic parameters serve as the greatest source of disagreement for pathologists provide a valuable framework for further refinement of the criteria for endometrial dating.Meanwhile, continued use of the criteria of Noyes et al for endometrial dating is recommended until more precise modalities for assessing the adequacy of endometrial maturation are available.

Variation in the cycle is usually due to differences in the proliferative phase as collapse of the secretory phase into menstruation if fertilisation does not take place is relatively more predictable than the proliferative phase.These changes are presumably due to the poor development of the corpus luteum.According to most investigators, measurements of serum progesterone levels rather than histological dating of the endometrium provide for the best assessment of LPD (see discussion later in this chapter).The final argument in favor of taking samples at the onset of bleeding is that endometrium of the first 2 days of menstruation is relatively easy to recognize histologically.